Nature Notes' Tony Drakeford talks about bluebells and the threats to Britain's favourite wildflower.

It's bluebell time once again.

Voted Britain's most loved wild flower, woodland floors are now carpeted with a blaze of deep blue and pervaded by a delicate subtle scent. Many "bluebell walks" are advertised these days and most people have a favourite woodland to visit.

My own special location is at Hatchlands, the National Trust property in Surrey, but closer to home there is also another smaller, less well known site at Fishponds Wood by Wimbledon Common, managed by London Wildlife Trust.

Click play to see the video among the bluebells in Fishponds Wood

Taking care not to trample the leaves, as this can deprive the plant of food and kill it, I love to sit quietly among bluebells on a warm sunny day.

With luck, yellow brimstone butterflies or delicate orange tips may flutter through the wood and hang upside down underneath a drooping flower to imbibe nectar.

Occasionally flowers may be pure white or even pink and the whole array of varying pastel shades is a visual delight.

But there are two worrying factors concerning the bluebell's future.

Firstly, like all spring flowers they need to bloom before the woodland canopy closes in and if warmer springs trigger an earlier opening of leaves above then that may deprive the plants of light and reduce their chances of photosynthesis.

Secondly, hybridisation is beginning to occur between our native bluebell and the imported Spanish variety, which is thicker stemmed and the flowers are a rather insipid pale blue without the attractive pendulous droop of our own beautiful blooms.